Apparatus for operating mine doors, switches, or the like



April Z1 1925.

l l E. H. GRIM .APPARATUS FOR OPERATING MINE DOORS, SWITCHES, OR THE LIKE s sheets-sheet 1 med June 2o, 192:5

ATTORNEY April 21', 1925.

' E. H. GRIM APPARATUS F011I OPERATING una DOORS, SWITCHES, 0R THE LIKE K Filed Jung, 2o. .192s s sheets-sheet z @MQW ` ATTORNEY l April 2l, 1925. 1,534,702

E. H. GRIM APPARATUS FOR OPERATING MINE DOORS, SWITCHES, 0R THE LIKE Filed June 20, 1923 f 3 Sheets-Sheet 3 INVENTOR award/166km.

ATTORNEY Patented Apr. 21, 1925.

UNITED STATES EDWARD H. GR-IM, 0F DOTT, WEST VIRGINIA.

APPARATUS FOR OPERATING MINE DOORS, SWITCHES, OR THE LIKE.

Application led .Tune 20, 1923. Serial No. 646,731.l

T0 all whom t may concern.'

Be it known that I, EDWARD H GrniM, a citizen of the United States, residing at Dott, in the county of Mercer and State of West Virginia, have invented certain new and useful Improvements in Apparatus for Operating Mine Doors, Switches, or the like, of which the following is a specification.

The invention resides in the provision of apparatus for controlling and indicating the movement of safety doors and switches such as are employed in mining operations and for movable elements of similar nature.

Primarily the invention has for its object to provide an apparatus of the class described which is of simple and relatively inexpensive construction and in which the parts are so constructed and correlatively arranged as to effect the desired movement of the mine doors or switches in a safe and positive manner and whereby the operation of the said moving elements may be effected from a distance.

In its-more detailed nature the invention has for its object the provision of electrically controlled means for operating mine doors and switches to permit the passing therethrough or thereover of the ore conveying cars. means mounted on the traveling cars whereby the operating means may be caused to function at the will of the operator riding on the cars and at any desired distance from the particular doors or switch, and means mounted on the traveling car and in view of the operator thereof for indicating the position of the distant doors or switch to be operated.

The invention further has for its object to provide electrically controlled and operated apparatus ofthe type stated in which the operating parts are driven by an electric motor, in which provision is made for preventing overloading of the motor during its operative function. in which the parts are so arranged as to permit a period of free. operation of the motor before strain of actual. operation is imposed thereupon, and wherein the-parts are so designed and arranged as to effect a positive locking of the elements to be moved to their various positions.

With the above and other objects inview the invention resides in those novel details of construction, combination and Varrangement of parte, alll of which will be fully described and then be specifically pointed out in the appended claims, reference being had l to the accompanying drawings, in which:

Figure l is a partly diagrammatic perspective view illustrating my invention in operation. y

Figure 2 is a cross section of the mine passage way illustrated in Figure 1,`looking in the direction of the safety doors.

Figure 3 is a cross section taken substantially on the line 3-3 on Figure 2.

Figure 4 is a diagrammatic plan view illustrating the wiring system. p

Figure 5 is a plan view of the control switch. y

Figure 6 is a detail horizontal section illustrating the double shaft gear connection. 1

Figure 7 is a `detail perspective view of one of the pendent doorbrackets.

Figure 8 is a detail horizontaly section illustrating a modified form of operating screw shaft.

Figure 9 is a diagrammatic front elevation illustrating a modified form of door operating means.

Figure 10 is a detail cross section illustrating the motor connection for the form of the invention shown in Figure 9.

Figure 11 is a somewhat diagrammatic plan view of my invention operatively applied to a mine switch. y

Figure 12 is a cross section takenacross the switch at the interval of the operating screw.

In the dra-wings my invention is illustrated as operatively applied within a mine passage and as especially adaptable fork operating safety doors or for controlling switches therein. IVliile the invention has been practically illustrated in the connection just stati ed it should be readily understood that the invention is not limited to this vuse but is applicable to cooperation with any moving .element such as comes within the scope of the appended claims.

In the adaptation of the invention as illustrated in the drawings` .l indicates a trackway over which the mine cars carrying the mined coal or ore are drawn through the medium of the usual electric locomotive i'.

It is common practice in mining at the present day to provide the mine passages at intervals with safety doors and in the drawings, see Figure 1, I have illustrated a mine passage as equipped with a safety wall 3, which may be supported in its proper relation with the mine walls by suitable timbers l such as are commonly used in this art. The cross wall et is provided with a suitable passageway or opening 5 through which the mine cars may pass, and this opening 5 is adapted to be closed normally, that is, While cars are not being drawn therethrough, by a pair of sliding doors 6 adapted to be guided, through the medium of door hangers 7 with which the doors are equipped, over a suitable guide rail S secured to the cross wall 3, and are adapted to meet and abut at the median line of the trackway 1.

The doors are equipped at their bottom edges with oppositely disposed pendent brackets 9, each of which includes a horizontally turned and elongated portion 10 provided with an elongated slot 11 disposed in the direction of the length of the doorsT see Figures 2 and 7 A door operating nut 12 is slidably mounted in each slotway 11, and the said operating nuts each including` an internally threaded bore, each adapted to receive one of a pair of cooperatively mounted operating screws 13 to which rotary motion is imparted from the motor 14e. The screws 13 are disposed in horizontal relation, one with the other, closely adjacent, and are joined to turn in opposite directions by small pinion gears 15 within the casing 16, which is mounted centrally of the cross wall 3, see Figures 1 and 2.

By reason of thus joining thel operating screws 13 by the pinions 15 the said screws may be made of the same pitch and when rotary motion is imparted to the same by the motor 11i the doors will be caused to move simultaneously, toward or from each other as the case may be, to open or close the passageway through the cross wall 3 to permit passage of the coal or ore laden cars through the said cross wall, or to close the safety doors immediately after the passage of the cars therethrough.

A friction slip clutch 17 is spliced between the motor shaft and the operating screws adjacent thereto so that should the motor remain energizec after the doors have reached either limit of their movement the transmission connections will be allowed to slip to prevent overloading and destruction of the motor.

By reason of the slot connection between the operating screws 13, the operating nuts 12 and the door brackets 9.. a certain degree of free movement of the motor is permitted before actual working strain, due to the actual door opening or closing switch. By permitting this `degree of free movement of `of the operating screws.

the motor the same is allowed to speed up slightly before strain is placed thereupon and the life of the motor is extended by reason of thus relieving the motor of eXtreme strain incident to the sudden shock of operation which would otherwise be placed thereupon.

The mine wall may be suitably cut-away and tunneled and the timber e constructed to straddle the cut-away portion to make suitable provisions for the positioning of the motor lele, see 18 on Figures 2 and 3.

In Figures 9 and 10 is illustrated a slight modification of the door opening and closing mechanism. In these figures the motor is positioned with the driving shaft thereof in close aligninent with the cross wall 3, and the said shaft is provided with a small driving pinion 19 adapted to mesh with a reduction gear 20, mounted on the door operating cross shaft 21, mounted in any suitable way at proper position adjacent the bottoni end of the cross wall "l as illustrated in the ligures referred to. The said operating shaft 21 is provided with a slip clutch connection and a small pulley 23 adapted to cooperate with a similar pulley mounted upon a cross shaft 2li disposed at the opposite bottom end of the cross wall 3. An endless operating rope is adapted to cooperate with the pulleys in effecting the opening and closing of the doors G and this endless rope 25 is wrapped once or more around each pulley 23 so that, when the motor is energized and rotary motion imparted thereby to the shaft 21. the endless rope 25 will be caused to take the course indicated by the arrows on Figure 9.

A bracket 26 is pendent from each door G and the said brackets are so arranged that one thereof cooperates with the upper travel` ling portion of the rope 25 and the other thereof cooperates with the lower travelling' rope 25, see Figure 9. rThe rope 25 may bc provided with abutments 2.7. a pair of which cooperate with each pendent bracket 26.

lilhen the motor is imparting rotary motion to the shaft 21 and thereby causing the rope to take the course indicated in Figure t), the respective abutments 2T will engage the pendent brackets 2G to effect the oipeiiing or closing. simultaneously, of the doors (i. It will be observed from Figure 9 that the abutments 27 are spaced some distance apart so as to allow a degree of free movement of the rope 25 before the actual opening or closing action is effected thereby. thus allowing a degree of free rotation olf the motor for the purpose hereinbefore described.

In Figure S is illustrated a modified form In this form of the invention a single operating screw 28 is employed, the same being provided with a double pitch so that rotation thereof in either direction will ei'ect a simultaneous opening or closing of the doors as desired.

The usual trolley wire is centrally disposed within the mine passageway so as to be in a central position when the doors are closed, as is clearly indicated in Figure l. From this trolley wire 30 is obtained electrical energy 'tor operating the locomotive which pulls the train of coal or ore laden cars, also the energy for operating the motor 14 and for energizing the circuit for lighting the indicator signal in the manner presently to be described.

It is a purpose of this invention to make it possible for the operator of the mine locomotive to operate the doors from a distance and also to provide an indicating means whereby it is possible for him to know whether or not the doors have been properly opened before he has approached the same too closely.

In carrying out these objects of the invention I provide a plurality, four being shown, of electrically energizable conducting wires, 3l, 32, 33 and 34, which are disposed at the side of and adjacent to the trackway l where they are suitably supported in the position shown in Figure l by suitable supporting brackets 35.

A contact making arm 36 is pivoted to the locomotive 2 in position for being raised into engagement with the wires 31, 32, 33 and 34, and the said arm is in the nature of a bell crank lever and is link connected, as at 38, to an operating lever 39 whereby the operator of the locomotive may conveniently lift the said arm into engagement with the said wires and a quadrant 40 is provided to cooperate with the lever to hold the same in the adjusted position so that the lever will slide along the wires and make electrical contact therewith -in the manner soon to be described. As before referred to an indicator light 4l is provided at a suitable position within the range of vision of the operator of the locomotife and means is provided for lighting this iight to indicate the position of the door before the locomotive has approached the same.

A control switch lever 42 is also mounted on the locomotive closely adjacent the lever 39 so as to be in convenient position for being operated by the driver of the locomotive for energizing the various circuits soon to be described.

By referring now more particularly to Figures l and; 4 it will be observed that the numeral 43 represents, in diagram, the motor field, 44 the armature winding, 45 the wire connecting one end of the field 43 with the trolley wire 30. The wire 46 connects the other end of the motor field with-the wire 32 which parallels the trackway l. rIhe two terminals of the armature winding are joined, one by the wire 47 to the wire 3l which parallels the trackway, and the other by the wire 48k with the wire 33 which parallels the trackway.

Suitably mounted upon a post or other supporting medium, such as is indicated in Figure l, I provide a normally open circuit maker 49 of the common two-part type and the said circuit maker is in alignment! with the line of travel of the adjacent door 6 and so positioned that when the door is forced open to the limit of its movement the same will engage the circuit maker to close the same. A wire 50 joins one terminal of the circuit maker 49 to a ground connection with the track rail. and the wire 5l joins the other terminal of the circuit maker to the wire 34 which parallels the trackway l. By reason of the engagement of the circuit maker 49 by the door, at the limit of its opening movement, lighting of the signal 40 on the locomotive 2 is effected through electrical connections and inthe manner later to be described.

The control switch lever 42 hereinbefore referred to cooperates with the control switch body 52 which is pivoted to the locomotive, as at 53, in 'position for being conveniently manipulated by the operator of the locomotive for controlling the operation of the door opening motor.

The switch body 52 includes a pair of cross contacts 54 so positioned as to leave a space therebetween on the under surface of the switch body 52 and being upturned aroundr the sides of the switch body as in indicated at 55.

lllO

A pair of side contacts 56 are secured to the locomotive body in a manner Jfor effecting ground connection therewith and in position for being engaged by the upturned portions 55 of the contacts 54 of the switch body as the same is moved to either side in themanner and for the purposes soon to be explained. It will be understood of course that the switch body 52 is constructed of suitable non-conductive material and properly insulated from the locomotive body.

A set of three contacts 57 cooperates with the switch contacts 54 and the same are disposed one at each side and in constant contact with the respective one of the movable contacts 54 and one disposed centrally thereof and projected into the blank space between the contacts 54, when the switch is in the normal position, so as only to be engaged when the switch body is moved to one side or another, see Figure 5.

It should be understood that the contacts 54 are also suitably insulated from the locomotive body.

Assuming the parts to be in the position illustrated in Figure 5, should the switch be moved toward the uppermost contact stop 56 as shown, it will readily be underwa y l.

the plete afiajted with one ot' the conii niiccts h engage with tl-`v 'r disposed contact 3T. A wire 3 "":i the co t plate 5S adaptci the wire HIT itli the other con- .iY wire (3;2 connects the conda )ted to engage with the with the indicating` liglt ie otl er terminal oi` the ionneGtPd Y y the i i the i or signal signal lieht 11 "23 with the wire centrall'v disposed part-s to be positioned as re l. that is` with the doors .osed positionr` by reason ott the relation ot the screws 13 with the operati nuts o" the respective doors and the swucli lever at its normal position and the contect making' arin 3G at its norma-l non-contacting` position, the inotor 14 would be rie-energized and all mechanism out of operation.

lilhile in the 'ligure re'terred to, the loconiotive is illustrated at a position tairlv7 close to the doors to be opened it is to be understood that the inechanisin of the invention is adapted to be operated troni any distance from these. doors for the purpose ot greater safety and 'for that purpose the indicating' light -l-'l is provided to indicate elearl,Y to the operator the position of the doors even before they have come into the range of his view.

Bv i'iulling down on the arin 39 the operi raises the arrn 86 into slidingjr contact with the wires Si, 33 and Sil parallelingi' the tracliway. Upon making this Contact iv the arin 3G with the said wires it is iiniiiediatcl possible 'for the operator to ascertain theiposition in which the doors are at that time.. Should the doors be at the open position the light lll would be lighted by reason ot the coinpleted circuit at i9 through the grounded wire 30, the wire 5l, the wire 2li the wire G2, through the light, through the wire (5?), through the Wire 60, through the wire through the Wire 46, through the motor field 43 and through the Wire 4:5 to the trolley 30.

Fhould the action oi lifting' the contact mal-ing arin reveal the Jfact that the safety doors were closed. as they should be, the operator would then proceed to set his switch to open 'the doors through the aotion ot the nio-tor and power transmission niechanisin hereinbeiore described in detaii, The direction in which the switch would he thrown depends oli course upon the winding' oi the armature and the pitch oi the op 'ating screws i3. By throwing the switch into Contact with the upper stop contar' 5o. indicated in Figure 5, it will be seen that a circuit will be completed bj; energ'izinsgl the inc/tor to cause rotation ot tue saiiic in a particular direction as 'tollow: Through the ground connection :'r', the cross contact plate 5i, the uppermost contact blade 57, the wires 59. 3l, il?, thriiufi'h the arn'iature winding, the wires llt. 232%. (il, the remaining' two contacts 57 and wires G0, 232T lf3.` through the motor ield et?) und through thel wire hl5 to the trolwire 30.

Vhcn the switch body 42 is shitted to the opposite position to that just above referred to, Yfor the purpose ot reversing the action oi1 the niotor, the circuit will be completed as follows. Through the lowerinost grounded stop contact 56, the cross contact 54, the lowernuist contact 5T. the wires Gl, 33, 48, fr?. 3l, 59, the reniai.' iing` two contact blades 5T, the wires G0, T52. 16, through the inotor ^field -l and through the wire l5 to the trolleyrv wire 30.

in Figures ll and l2 the invention is illustrated as applied in connection with a inine switch. ln this illustration (Se indicates the straight trackivay, the curved tracliwzilv cooperative therewith and 6G the switch or io'ahlo element adapted to be shifted troni one position to the other jv action oi the niotor with the application of' the peculiar mechanism or' my invention.

The inotor is indicated at GT and the drive shaft G8 thereof is ioined by a triction slip clutch connection Gf) with the operating' shaft portion TO which is properly threaded at the desired pitch.

"lhe individual parts of the movable switch element GG are joined by the cross plate 7l which is provided with a longitudinal slotwajii 'T2 'tor providing a lost motion connection for thc operating` nut T3 provided with an internnllj,7 threaded bore for zeconnnodating the threaded portion of the operating screw 70.

ln this lorin o' locomotive 9?) may be provided with a pair ot indicating' signals or lights as indicated at il and which, `for example, may be red and green lights, one to indicate the clear position of the track and the other to indicate the danger position or open switch.

ln this torni of the invention a set ot lll() circuit contact wires are also provided. par# motor iield is designated at 82 and the motor armature winding is designated at 83. One terminal of the motor field 82 is in electrical communication with the trolley wire 81 through the medium of the wire 84 and the other terminal of the motor field is in electrical communication through the wire 86 with the wire 77 which parallels the trackway. The. terminals of the armature winding are in electrical communication with the wires 7 6 and 78 which parallel the trackway 64 through the medium of the wires and 87 respectively. It will be 'readily apparent, by reference to Figure 11, that as the switch block, hereinbefore described in detail, is moved to one side or the other from its neutral or switch cle-energized position the lnotor will be energized and caused to operate in a direction in accordance with the side to which the switch block was moved through the various wires just described in like manner as hereinbefore described in detail in connection with the door operating mechanism.

For providing for the proper energization of the signals 74 and 75 the operating nut 73 is ground connected, as at 88, to one of the track rails 64. The operating nut 73 is also provided with a contacting finger 89 which is adapted to engage at either of its limits of lateral movement with a pair of contacts 90, each of which cooperates with the respective one of the indicating signals 74-75 above referred to. One of the contacts 90 is joined by a wire 91 with the wireV 79 which parallels the trackway and the other of the contacts 90 is joined through the medium of the wire 92 with the remaining wire 80 which parallels the trackway.

In this form of the invention the contact making bar 94 is provided with a suitable number of contacting plates to correspond with the number of wires paralleling the trackway, that is, five, and the. oneof these contacts which is adapted to engage the wire 7 6 is joined by a wire 96 with one of the contacts 75 of the switch contact mechanism. The one of these plates which is adapted to slidably engage the wire 77 is connected by the wire 97 with the centrally disposed one of the contact blades 75, the one adapted to slidably engage the wire 78 is joined through the medium of the wire 98 with the remaining one of the contact blades 75, the one thereof which is adapted to slidably engage the wire 79 is joined through the medium of the wire 99 with one terminal of the indicating signal 74, and the one thereof which is adapted to slidably engage the Wire 80 is joined through the medium of the Wire 100 with one terminal of the indicating signal 7 The remaining termi nals of each of the indicating signals 74 and 7 are joined together by a cross wire 101, and this cross wire 101 is in turn electricallyV connected, through the medium of the wire 102, with the wire 97 which connects with the centrally disposed contact 75 and the wire 77 which parallels the trackr Way 64.

It will be readily apparent, by reference to Figure 11, that when the switch mechanism has been moved to the position indii cated in that iigure and with the contact block 73 over in position for having its contact lingers engage the contact 90 farthestto the right in that figure, and the contact making arm 94 raised, that a complete electric circuit will be made such as will venergize the particular signal 7 5 through the ground connection and the Wire 88, through the block 73, the finger 89, that particular contact 90, its connecting wire 92, the wire 80, the vwire 100,' through the signal 75, the short portion of the cross overwire 101 between the light 7 5 and its connection with the wire 102, through the wire 102, the wire 98, the wire 77, the wire 85, through the field 82 of the motor and through the wire 84 to the trolley wire 81. By reference to the said figure is will be observed that when the operating nut 73 is in its opposite position the light 74 will be brought into play in the same manner as above indicated and through its respective wiring circuit. v

By reason of providing this threaded operating shaft for moving the movable element, either switch or doors, it will be readily apparent that the said element is held locked at either limit of its movement and in fact at any portion of its movement if it should be desired to open'the doors partially which, however, is not the case in the preferred operation of the system disclosed.

Also by providing the element shifting means with a lost motion feature it will be readily understood that the motor is given a chance to properly pick up speed before the strain of actual operation, incident to the moving of the movable element, is placed upon the motor.'V

While I have illustrated my invention as particularly adapted for operation of mine doors and switches it is evident that the invention may also be used for operating switches of surface railroads and for operating grade crossing gates and the like, and I do not wish to be limitedto the particular uses of the invention illustrated but de sire it understood that my invention is use- From the foregoing description, taken in connection with the accompanying drawings, the complete construction, operation and advantages of my invention will be clear to those skilled in the art to which it appertains.

What I claim is:

l. In mine door and switch operating systems, the combination with the element to be opened or closed, oi an electric motor for opening' and closing the same, electric circuit controlling means on a mine car for effecting the action 0i said motor as the car approaches the element to be opened or closed, and signalling instrumentalities including signals on the car and signal operating devices associated with the element to be opened or closed, for indicating to the operator on the car the position of said element.

2. In mine door and switch operating systems, the combination with the element to be opened or closed, or' an electric motor ior opening and closing the same, connections between said motor and said element to be opened or closed, said connections including means to loclr said element in the open or closed position electric circuit controlling means on a mine car for effecting the action of said motor as the car approaches the element to be opened or closed, and signalling instrumentalities including signals on the car and signal operating devices associated with the element to be opened or closed, for indicating to the operator on the car the position of said element.

3. In mine door and switch operating systems, the combination with the element to be opened or closed, oi an electric motor for opening and closing the same, electric circuit controlling means on a mine car for effecting the action ot said motor as the car approaches the element to be opened or closed, connections between said electric motor and said element including a lost motion device to permit the motor to pick up before moving said element and including means to lock said element in the open or closed position, and signalling instrumentalities including signals on the car and signal operating devices associated with the element to be opened or closed, for indicating the position ot ,said element.

4. In mine door and switch operating systems, the combination with'the element to be opened or closed, ot an electric motor, power transmission connections including a delayed-action device between said electric motor and the clement to be opened or closed whereby said motor will move said part, a trackway through the mine passage, an electrically propelled vehicle movable over the trackway, a trolley wire ior supplying electrical energ t to the vehicle, a set ot' fixed circuit contacts paralleling the trackwayv and adjacent thereto, means whereby the trolley wire, the motor and the set ot circuit contacts are in electrical communication in a `broken circuit, and means on the movable vehicle 'tor engaging the set ot tixed circuit contacts for completing the circuit. to energize the motor, as the vehicle is approaching the position of the element to be opened or closed, a signal on said vehicle, tor indicating the position ot' element to be opened or closed and an electrically energized broken circuit adapted to be completed by the circuit completing means and by the movement ot the element to be opened or closed tor effecting the indicating function of said signal.

5. In mine door and switch operating tems, the combination with the element to be opened or closed, of an electric motor` power transmission connections including a delayed-action device between said electric motor and the element to be opened or closed whereby said motor will move said part, a tracltway through thc mine passage, an electrically propelled vehicle movable.. over the traclnvay, a trolley wire l'or supplying electrical energy to the vehicle, a set oliI fixed circuit contacts paralleling the trackway and adjacent thereto, means whereby the trolley wire, the motor and the set of circuit contacts are in electrical communication in a broken circuit, a contact making arm mounted on the movable vehicle and adapted to be lifted into engagement with the set of fixed contacts, a control switch mounted upon said vehicle and adapted tor effecting a reversal ot' the motor, and elec` trical connections between said switch and said contact making arm.

G. In mine door and switch operating systems, the combination with the element to be opened or closed, of an electric motor, power transmission connections including a dcla ye .laction device between said electric motor and the element to be opened or closed whereby said motor will move said part, a tracliway through the mine passage, an electrically propelled vehicle movable over the trackway, a trolley wire for supplying electrical energy to the vehicle, a set ot' lixcd circuit contacts paralleling the trackway and adjacent thereto, means whereby the trolley wire the motor and the setof circuit contacts are in electrical communication in a broken circuit, a contact making arm mounted on the movable vehicle and adapted to be lifted into engagement with the set ot' iixed Contacts, a control switch mounted upon said vehicle and adapted for effecting a reversal ot the motor, and electrical connections between said switch and said contact making arm, a signal on said vehicle for indicating the position of the element to be opened or closed, and an electrically energized broken circuit adapted to be completed by the switch and circuit completing arm and by the movement ol the element to be opened or closed.

7. A mine door and switch operating system comprising the following elements in combination with the element to be opened or closed, an electric motor, power transmission connections including a delayedaction device between said motor and the element to be opened or closed whereby said motor will move said part, a trackway through the mine passage, an electrically propelled vehicle movable over said trackway, a trolley wire for supplying electrical energy to the vehicle, a set of lixed circuit contact wires supported longitudinally of and parallelly adjacent the trackway, an electrical connection between the trolley wire and the motor field, an electrical connection between the lsaid motor field and one oi' the set of circuit contact wires, an electrical connection between one end of the motor arma-ture winding and one oi the set ot' circuit contact wires, an electrical connection between the other end of the armaturev winding and one of the set of circuit contact wires, a contact making arm mounted upon the movable vehicle and adapted to be moved into slidable engagement with" the set of circuit cont-act wires, and a control switch means mounted on said movable vehicle for completing and energizing or de-energizing the various circuits ormed by the said connections 8. A mine door and switch operating system comprising the following elements in combination with the element to be opened or closed, an electric motor, power transmission connections between said motor and the element to be opened or closed whereby said motor will move said element, a trackmy through the mine passage, an electrically propelled vehicle movable over said trackway, a. trolley wire for supplying electrical energy to the vehicle, a set of lined circuit contact wires supported longitudinally of and parallelly adjacent the trackway, a two-part electric contact adapted to be actuated by said element to be opened or closed during its course of travel, an electrical connection between one part of said twopart contact and ground, an electrical connection between the other part of the twopart contact with one of the set of iiXed circuit contact wires, an electrical connection between the trolley wire and the motor field, an electrical connection between the said motor lield and one of the set of circuit contact wires, an electrical connection between one end of the motor armature winding and one of the set of circuit contact wires, an electrical. connection between the other end of the armature winding and one of the set of circuit Contact wires, an indicating signal mounted upon the movable vehicle lfor indicating the position of the element to be opened or closed, a contact making arm mounted upon the movable vehicle and adapted to be moved into slidable engagement v ith the set oil circuit Contact wires, an electrical connect-ion between said signa-l and said arm, and a control switch means mounted on said movable vehicle for completing and energizing the various circuits formed by the said connections. i

9. In a mine door operating system wherein is provided an electric motor and an electric control circuit governed by mechanism on a mine car; the combination with a pair of doors to be opened and closed by said electric motor, of operating screws driven byv said motor, means pendent from the doors and cooperative wit-h the operating screws whereby the doors will be caused to move simultaneously toward or from each other by rotation oit said screws, said connections including a lost motion device whereby the momentum oi said motor may be attained before power is applied from the screws to move the doors.

l0. In a. mine door operating system, the combination with a pair of doors to be opened and closed, of an electric motor, operating screws driven byfsaid motor, slip clutch connections between. said motor and said screws for preventing overloading of said motor, brackets pendent from the doors and cooperative with the operating screws whereby the doors will be caused to move simultaneously toward each other by rotation of said screws, means for providing lost motion in the connection between the bracket and screw connection for the doors, a movable vehicle, a motor circuit control on said vehicle, and means for e'lfecting operative electrical connection between said motor and said vehicle as said vehicle approaches the place where the doors are located, and signaling instrumentalities including signals on the movable vehicle and signal operating devices associated with the doors to be opened and closed, for indicating the position of said doors.

1l. In a mine door operating system, the combination with a pair of doors to be opened and closed, of an electric motor, operating screws driven by said motor, slip clutch connections between said motor and said screws for preventing overloading of said motor, brackets pendent from the doors and cooperative with the operating screws whereby the doors will be caused to move simultaneously toward each other by rotation of said screws, means for providing lost motion in the connection between the bracket and screw connection for the doors, a movable vehicle, a motor circuit control on said vehicle, a set of fixed 'circuit conlill) llO facts connected with said inotoi7 a movable Contact element on said vehicle adapted to be moved into engagement with said lixed circuit -coiitacts as the said movable vehicle passes the saine to effect connection between Said circuit contacts and Said inotoi to opeiate the saine at the will of the operator,

and signaling instrumentalities including signals on the movable vehicle and signal operating de vices associated With the doors 10 to be opened and closed, for indicating the position of said doors.

EDVARD H. GRIM. 

